This section provides background information relating to the present disclosure, which is not necessarily prior art.
Under the conventional scene of carrier aggregation within a base station, a PUCCH (Physical Uplink Control Channel) can be transmitted only on a PCC (Primary Component Carrier) of a Pcell (Primary cell), a PUSCH (Physical Uplink Shared Channel) and an SRS (Sounding Reference Signal) may be transmitted on the PCC of the Pcell or an SCC (Secondary Component Carrier) of an Scell (Secondary cell), and a PRACH (Physical Random Access Channel) signal is transmitted only when a certain carrier is to be connected to a terminal. Generally, the terminal and the PCC maintain a connection state, and the SCC is connected to the terminal in a case that the PCC is successfully connected to the terminal. In addition, UCI (Uplink Control Information) is transmitted by only one PUSCH within one subframe, and the SRS is transmitted only once within one subframe in a case that multiple aggregated carriers share one TA. Particularly, in case of transmitting the PRACH, the terminal does not transmit the PUCCH/PUSCH/SRS signal simultaneously.
Under a scene of carrier aggregation for inter base-station for non-fiber direct connection or dual connectivity, since real time scheduling coordination inter base-station cannot be performed, resulting in that a probability of exceeding the maximum transmission power in uplink transmission is higher as compared with the scene of carrier aggregation for intra base-station. Presently, there is no good solution as to the above issue, and thereby resulting in reducing of uplink/downlink transmission efficiency.